From 0e48f51cbbfbdb79149806de14dcb8bf0f01ca94 Mon Sep 17 00:00:00 2001
From: Mika Westerberg <mika.westerberg@linux.intel.com>
Date: Fri, 4 Oct 2019 13:00:25 +0300
Subject: [PATCH] Revert "libata, freezer: avoid block device removal while system is frozen"
Git-commit: 0e48f51cbbfbdb79149806de14dcb8bf0f01ca94
Patch-mainline: v5.4-rc3
References: git-fixes
This reverts commit 85fbd722ad0f5d64d1ad15888cd1eb2188bfb557.
The commit was added as a quick band-aid for a hang that happened when a
block device was removed during system suspend. Now that bdi_wq is not
freezable anymore the hang should not be possible and we can get rid of
this hack by reverting it.
Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Acked-by: Takashi Iwai <tiwai@suse.de>
---
drivers/ata/libata-scsi.c | 21 ---------------------
kernel/freezer.c | 6 ------
2 files changed, 27 deletions(-)
diff --git a/drivers/ata/libata-scsi.c b/drivers/ata/libata-scsi.c
index 76d0f9de767b..58e09ffe8b9c 100644
--- a/drivers/ata/libata-scsi.c
+++ b/drivers/ata/libata-scsi.c
@@ -4791,27 +4791,6 @@ void ata_scsi_hotplug(struct work_struct *work)
return;
}
- /*
- * XXX - UGLY HACK
- *
- * The block layer suspend/resume path is fundamentally broken due
- * to freezable kthreads and workqueue and may deadlock if a block
- * device gets removed while resume is in progress. I don't know
- * what the solution is short of removing freezable kthreads and
- * workqueues altogether.
- *
- * The following is an ugly hack to avoid kicking off device
- * removal while freezer is active. This is a joke but does avoid
- * this particular deadlock scenario.
- *
- * https://bugzilla.kernel.org/show_bug.cgi?id=62801
- * http://marc.info/?l=linux-kernel&m=138695698516487
- */
-#ifdef CONFIG_FREEZER
- while (pm_freezing)
- msleep(10);
-#endif
-
DPRINTK("ENTER\n");
mutex_lock(&ap->scsi_scan_mutex);
diff --git a/kernel/freezer.c b/kernel/freezer.c
index c0738424bb43..dc520f01f99d 100644
--- a/kernel/freezer.c
+++ b/kernel/freezer.c
@@ -22,12 +22,6 @@ EXPORT_SYMBOL(system_freezing_cnt);
bool pm_freezing;
bool pm_nosig_freezing;
-/*
- * Temporary export for the deadlock workaround in ata_scsi_hotplug().
- * Remove once the hack becomes unnecessary.
- */
-EXPORT_SYMBOL_GPL(pm_freezing);
-
/* protects freezing and frozen transitions */
static DEFINE_SPINLOCK(freezer_lock);
--
2.16.4